My interests are in the cellular and molecular mechanisms responsible for acute lung injury and the pathways that may ameliorate lung injury. Over the past two years I have worked in Dr. Elias's laboratory pursuing these interests. My work as detailed in the enclosed proposal, has focused on the mechanism(s) of protection that IL-11 confers in the setting of hyperoxic lung injury. We compared the susceptibility to 100% oxygen of transgenic mice in which IL-11 is over-expressed in an airway-specific fashion and animals live significantly longer in 100% oxygen and this protective effect is associated with diminished ultrastructural evidence of endothelial injury, alveolar protein leak and lipid peroxidation, while alterations in antioxidants are not of a magnitude to explain this effect. The protective effects of IL-11 are associated with a significant decrease in hyperoxia-induced apoptosis and the enhanced expression of, Bcl-2. These studies lead us to hypothesize that IL-11 is protective in the setting of hyperoxic lung injury and this protection is mediated, in part by the inhibition of apoptosis and in part, by the inhibition of the inflammatory response. To test this hypothesis, we propose to Aim # 1: Compare the expression, in vivo, of apoptosis regulators in CC10-IL-11 transgene (+) and littermate control mice before and after exposure to 100% oxygen. We will compare the expression of protein regulators of apoptosis in transgene (+) and (-) animals at the mRNA and protein levels; when possibly, clarify the roles of these regulators by characterizing the O2 tolerance of mice with targeted genetic disruptions and mice that over express specific regulators. Generate and characterize the O2 tolerance of crosses of CC10-IL-11 animals and the genetically modified mice noted above. Characterize the state of activation of the NF-kB system in transgene (+) and (-) mice. Aim #2: Establish an in vitro system that can be used to define the mechanism of hyperoxia-(oxidant) induced apoptosis and the protective effects of IL-11. Studies will be undertaken to define whether pulmonary epithelial and/or endothelial cells (primary cultures of cell lines) that undergo apoptosis in the presence of oxidant stress are protect from apoptosis by IL-11. If apoptosis is noted and IL-11 protection can be documented, the expression of regulators of apoptosis will be described as above. In addition, the contributions that each of these moieties makes in this in vitro system will be investigated by taking advantage of our ability to: (a) transfect and over express these moieties and (c) use anti-sense approaches to prevent the induction of potential apoptosis regulators. Aim # 3: Characterize the mechanism(s) responsible for the inhibition of granulocyte recruitment to the lung in CC10-IL-11 transgene (+) mice. We will determine if IL-11, in the presence or absence of 100% O2 inhibits the production of cytokines, leukotrienes, and the expression of adhesion molecules involved in granulocyte recruitment. Aim # 4: Determine the extent to which lung leukotrienes are involved in the pathogenesis of hyperoxic lung injury and the protection induced by IL-11 in this setting. We will determine if inhibitors of leukotriene metabolism mimic the protective effects of IL-11 in the setting of 100% O2. My major goal is to pursue a career in academic medicine that combine bench research, teaching, and patient care. I see such a career as the ideal way for me to combine my background in basic science with my clinical interest in pulmonary and intensive care medicine. I expect to continue to investigate the cellular and molecular mechanisms of acute lung injury with the hope that I will be able to directly apply the future findings to the care of patients. The training program outlined in this proposal will further my understanding of the mechanisms of pulmonary disease while providing the necessary molecular tools with which I can evolve into an independent investigator.